I don't understand what makes Haye seem invincible? What are Haye's positives besides of course his tee-shirt making ability?

His most exciting wins were over a worn out Jean Marc Mormeck who had previously gone life and death with O'Neil Bell and Enzo Mac who was probably the most overhyped fighter ever in the cruiserweight division. And Mormeck put Haye down! If Mormeck can do it, how about a strong heavyweight?

Haye is also notable for having a rough time with 36 year old 5'9 1/2 Fragomeni (not a bad fighter but horribly outsized and much older) and being knocked out by Carl Thompson.